Apparatus for bending the ends of terminal leads or the like



March l, 1960 A. B. CLEWES APPARATUS FOR BENDING THE ENDS OF TERMINAL LEADS 0R THE LIKE Filed April 15, 1957 F/G. P.

United States Patent O APPARATUS FOR BENDING THE ENDS F TERMINAL LEADS OR THE LIKE Antony Brasher Clewes, Wollaton Park, England, as-

signor, by mesne assignments, to United-Carr Fastener Corporation, Boston, Mass., a corporation of Delaware Application April 15, 1957, Serial No. 652,800 Claims priority, application Great Britain April 18, 1956 l Claim. (Cl. 1-210) This invention relates to assemblies which include an apertured support having one or more articles mounted thereon, the article or articles being provided with projecting metal leads adapted to extend through apertures so as to project from the opposite face of the support to that on which the article or articles are located. More particularly the invention relates to apparatus for bending the projecting ends of the metal leads into engagement with the said opposite face of the support. The invention is particularly applicable for assemblies including a panel having an electrical circuit diagram printed, etched or otherwise marked on one face and in this case the apparatus serves to bend the metal leads and press them into engagement with an appropriate part of the printed circuit diagram.

It is known to assemble valve, etc., holders on a panel having a printed circuit diagram to cause the ends of terminal prongs in the holder to extend through apertures in the panel so that they can be subsequently attached by soldering to portions of a printed circuit diagram on the panel. Heretofore the ends of the terminal p-rongs have projected axially of the panel apertures and substanti-ally normal to the plane of the panel. This, however, produces diicultics in effecting a dip soldering operation as it is necessary for the solder to bridge the gap between the sides of the aperture and the prong positioned therein and unless the terminal prong substantially lls the aperture, which is not always possible in practice, it is extremely ditlicult to effect by soldering an ecient mechanical and electrical connection between the terminal prong and the circuit diagram.

According to the present invention an electrical component provided with projecting terminal leads is assembled on an apertured support having an electrical circuit diagram printed, etched or otherwise marked on at least one face by a method which includes mounting the component on the support so that the leads extend through an aperture therein and project outwardly of the face thereof formed with the circuit diagram` bending the projecting portion of each lead outwardly to form an acute angle with respect to thc adjacent face of the support, and operating on the bent portion of the lead to cause the end portion thereof to be pressed into abutting engagement with the face of the support.

The method may include the steps of bending the projecting portion of each lead outwardly to form an acute angle with respect to the adjacent face of the support, bending the outer ends of said projecting portion of the lead towards the support to produce a bight portion adjacent the support aperture and a flat end portion extending radially outwardly of the bight and substantially parallel to thc adjacent face of the support and applying pressure to said llat end portion to press it into intimate contact with a part of the circuit diagram marked on the support.

The invention also includes apparatus for assembling an electrical component on a support having an electrical diagram printed, etched or otherwise marked on at least Patented Mar. l, 1960 one face and wherein the component is provided with projecting terminal leads extending through apertures in the support for electrical connection to parts of the said diagram, the apparatus including a ram movable relative to the project-end of the leads and operable to spread them outwardly so that they extend at an acute angle to the adjacent face of the support, means movable relatively to the ram for engaging the end portion of the leads to bend them towards the support to form a bight portion adjacent to the respective support aperture and a flat outer end portion extending radially outwardly of the bight and in a plane substantially parallel to the said face of the support and means for engaging said at outer end of the leads and operative to press said end into intimate engagement with a portion of the electrical diagram on the said face of the support.

To enable the invention to be fully understood it will now be described with reference to the accompanying drawing, in which:

Fig. 1 is a sectional side view of apparatus according to one embodiment of the invention showing a valve holder assembled on a panel and located by part of the apparatus;

Fig. 2 is a sectional side view of the apparatus of Fig. 1 but illustrating the tirst stage in the lead bending operation;

Fig. 3 is a similar view to Fig. 2, but illustrating the nal stage ofthe bending operation; and

Fig. 4 is a fragmentary view on an enlarged scale, illustrating the shape and position of the projecting end of the lead after the bending operation has been completed.

As described with reference to the accompanying drawing the apparatus is adapted for operating on the terminal leads 1 projecting from contacts 2 which are mounted in prong receiving bores 3 of a thermionic valve holder a, the latter being assembled on a panel b. As shown the leads 1 extend axially through apertures 4 in the panel and the underface bl of the latter has an electrical circuit diagram (not shown) printed, etched or otherwise marked thereon, parts of the circuit diagram extending to adjacent the apertures 4. The holder is also provided with a central hollow shield member 5 having resilient shoulder portions 6 adapted to make snapping engagement in an aperture 7 in the panel.

The ends of the leads 1 need to be bent so as to overlie appropriate parts of the printed diagram and as shown the apparatus for effecting this comprises a twopart tool, one part consisting of a body 8 having an open ended cavity 9 to receive and locate the valve holder a, the body having an axially extending stem 10 which is adapted to be connected with suitable means for moving the body in a vertical direction. The holder is preferably pre-assembled on the panel and the tool body 8 positioned to receive the valve holder a within the cavity 9 and an axially slidable rod 11 is moved to extend through a hollow rivet 5 for a purpose to be described.

A second tool part is located beneath the panel and comprises a hollow base member 12 housing a member 13 formed with an upstanding cylindrical wall or sleeve 14 the upper edge of which is formed with a tapered or conical surface 15. A ram 16 is mounted within the sleeve 14 so as to be movable axially therein, the ram being urged upwardly by a spring 17 and the extent of this upward movement being limited by a nut 18 which is adjustable on a threaded shank 19 extending integrally from the undersurface of the ram. It will be noted that the shank 19 extends through a central aperture in the upper wall of the member 13 and projects into a cavity 13a so that the upward movement of the ram is limited by the nut abutting the under side of the upper wall of the said cavity. The extent of the upward movement is readily varied by adjusting the nut on the shank. As shown the ram is of frusto-conical shape, the sloping wall 20 having the same angle as the surface 15 of the sleeve 14 so that in effect the surface 15 forms a continuation of the conical wall 20.

An outer sleeve member 2l is mounted on the outer periphery of the sleeve and located by means of an in ward annular shoulder 22 underlying the projecting edge of the surface of the sleeve. The outer sleeve 21 is urged upwardly to maintain the shoulder 22 in abutment with the said edge of the sleeve by a spring 23.

In operation the body 8 of the lirst tool part is positioned over a valve holder which has been pre-assembled on the panel b and the second tool part is positioned beneath the panel as indicated in Fig. 1. For initially setting the tool pat'ts in correct relative position the rod 11 may be moved downwardly and aligned with the recess 16a in the ram 16. The first tool part is then moved towards the second by suitable means and carries with it the panel and the assembled holder. As the assembly is moved towards the second tool part, the latter being held stationary, the outer ends of the leads 1 will first be engaged by the conical Wall 20 of the ram which will serve to bend them outwardly as they ride over the said conical face and over the conical face 15 of the sleeve 14 so that they will reach the position illustrated in Fig. 2.

At this point in the operation the underface b1 of the panel engages the upper end of the ram and continued downward movement of the assembly causes the ram to be forced inwardly of the sleeve against the pressure of the spring 17. The sleeve 14, however, remains stationary and accordingly its upper edge 15a engages a portion of the lead spaced inwardly of its extreme outer end and bends the end portion of the lead to produce a bight 1a at a point adjacent to the aperture 4 of the support, and a flat end portion Ib which extends radially outwardly in a plane substantially normal to the portion of the lead disposed within the aperture and substantially parallel to the underface b1 of the support. Finally the at end portion 1b of the lead is pressed by the upper end of the sleeve 14 into intimate engagement with part of the electrical circuit diagram marked on the underface b1 of the panel.

It will be noted that the outer sleeve 21 is resiliently mounted by the spring 23 so as to permit said outer sleeve to be moved relatively to the inner sleeve.

The bending operation effected by the apparatus as described will cause the end of the lead to assume the position illustrated in Figs. 3 and 4 wherein the outer end 1b of the lead is pressed against the underface b1 of the panel and presents a relatively broad fiat area overlying the appropriate part of the circuit diagram.

As the apertures 4 in the panel b will normally have a greater diameter than the leads 1, the portion of the leads disposed in the aperture will tend to be tilted laterally outwards into abutment with the outer edges of the aperture as their ends are bent by the ram. As the prongs are normally made of resilient sheet metal, there would normally be a tendency for them to spring inwardly again when the tool is removed with the consequent danger that the flattened ends 1b of the prongs would be moved out of contact with the circuit on the panel. This is, however, obviated by providing that the inner diameter of the outer sleeve 21 is such that when the ends of the prongs are bent outwardly by the ram, they will contact the inner surface of the outer sleeve so that the outward tilting movement of the leads in their aperture `4 is prevented. It will be noted that the ends of the leads remain in contact with the inner surface of the outer sleeve as they are bent by the sleeve, their outer ends scraping over the said inner surface. As the leads are restrained against lateral outward movement, their ends will be bent substantially at right angles with the result that when the tool is removed the said ends will remain in frictional contact with the appropriate part of the printed circuit.

At the completion of the bending operation the panel and assembled holder are removed and the panel is then subjected to a dip soldering operation to effect a permanent solder connection between the leads and the parts of the c uit diagram and in this soldering operation the should.;. of the hollow rivet is also soldered to an appropriate part of the diagram.

While a press tool has been described for mounting the individual valve holders it will be understood that where a series of holders are to be assembled on a panel a series of two-part tools will be provided so that the projecting leads of the series Vof holders can be simultaneously bent and pressed into engagement with the appropriate parts of the circuit diagram on the panel.

The invention is particularly applicable for assembling thermionic valve holders but it will be understood that it is not limited in this respect as it may be used for assembling other electrical components or other articles having projecting leads adapted to be bent into close engagement with the underface of an apertured support.

lf desired the first mentioned tool part may be fixed and the second tool part adapted to be moved relatively thereto.

I claim:

Apparatus for assembling an electrical component on a support having an electrical diagram wherein the component is provided with projecting terminal leads extending through apertures in the panel, the apparatus including a resiliently mounted ram having a conical face movable relative to the projecting ends of the leads to spread them outwardly so as to extend at an acute angle to the face `of the support formed with the diagram, an inner sleeve means receiving said ram and movable relative to the ram for engaging the end portions of the leads to bend them towards the support so as to produce a bight portion adjacent to the aperture and a flat outer end portion extending outwardly of the bight in a plane substantially parallel to the said face of the support, said inner sleeve means engaging said outer end of the leads and operative to press them into intimate engagement with a portion of the diagram on the said face of the support, and an outer sleeve member receiving said inner sleeve and slidable relative thereto, said outer sleeve being in encircled engagement with the free outer edges of said leads to limit the outer spread of said leads by said ram.

References Cited in the le of this patent UNITED STATES PATENTS 355,995 Joyce Ian. 11, 1887 447,314 Grunich Mar. 3, 1891 572,293 Greenfield Dec. l, 1896 

